SiGe Waveguide Modulator Vertical Field Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in the construction of optical modulators and photodiodes in planar lightwave circuits is the complexity and cost associated with manufacturing, particularly for SiGe devices, where a common structure is needed to simplify design and integration, while maintaining performance and ease of manufacture.
Innovation Solution
An optoelectronic component with a waveguide ridge structure, featuring doped regions that generate a vertical electric field, allowing for easier manufacturing and integration, utilizing a silicon-on-insulator platform and optically active materials like Ge or SiGe, which can function as both a modulator and photodiode by controlling optical absorption through applied electric fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vertical field devices are used, then field effectiveness is improved, but manufacturing complexity increases
Solution Approach 1:
The patent transitions from conventional lateral electrode configuration to a vertical field configuration by positioning electrodes at the top and bottom surfaces of the waveguide. This dimensional change creates a vertical electric field that is more effective for electro-absorption modulation while maintaining compatibility with standard semiconductor fabrication processes through epitaxial growth of doped regions.
Solution Approach 2:
The patent introduces locally doped regions within the waveguide structure, where specific portions of the waveguide are doped with n-type or p-type materials to create localized electric fields. This allows the field to be concentrated where needed for optimal modulation performance while keeping the rest of the structure simple and easy to manufacture.
2Adaptability or versatility
If integrated SiGe devices are used, then device functionality is improved, but manufacturing cost increases
Solution Approach 1:
The patent creates a universal waveguide structure that can function as both an optical modulator and a photodetector by incorporating SiGe material with appropriate doping. This multi-functional design eliminates the need for separate devices, reducing overall manufacturing cost and complexity while providing versatile functionality for both modulation and detection applications.
Solution Approach 2:
The patent merges the modulator and photodetector functions into a single integrated structure using SiGe material. By combining these functions in one device with a unified waveguide structure and electrode configuration, the patent reduces the number of discrete components needed, simplifying integration and reducing manufacturing costs.
3Ease of manufacture
If lateral contacts are used, then ease of manufacture is improved, but field effectiveness decreases
Solution Approach 1:
The patent changes the electrode configuration from lateral contacts to vertical contacts positioned at the top and bottom surfaces of the waveguide. This dimensional change enables the electric field to be applied vertically through the waveguide thickness, creating a more effective field configuration that enhances electro-absorption modulation while still being manufacturable using standard semiconductor processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design simplifies the manufacturing process, enhances performance by allowing for vertical electric field generation, and enables efficient operation as both a modulator and photodiode, achieving high speed and low power consumption with improved ease of integration.
Implementation Method 1
For modulators with a silicon/germanium (SiGe) medium, the Franz-Keldysh (FK) effect with lumped electrodes is used to achieve small size, high speed, low driving power consumption and ease of manufacture
Implementation Method 2
In other embodiments, the OAR is formed from a light absorbing medium suitable for generating a current upon detection of light when a voltage bias is applied across the upper and lower doped regions. In this way, the optoelectronic component functions as a photodiode.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
An optoelectronic component including a waveguide, the waveguide comprising an optically active region (OAR), the OAR having an upper and a lower surface; a lower doped region, wherein the lower doped region is located at and/or adjacent to at least a portion of a lower surface of the OAR, and extends laterally outwards from the OAR in a first direction; an upper doped region, wherein the upper doped region is located at and/or adjacent to at least a portion of an upper surface of the OAR, and extends laterally outwards from the OAR in a second direction; and an intrinsic region located between the lower doped region and the upper doped region.